[pkg-ntp-maintainers] Bug#731976: Bug#731976: ntpdate: Please use flock(1) in /etc/network/if-up.d/ntpdate

[Aurelien Jarno]

control: tag -1 + patch

On Tue, Sep 16, 2014 at 10:07:46PM +0200, Aurelien Jarno wrote:
> control: severity -1 important
> 
> On Wed, Dec 11, 2013 at 11:45:25PM +0100, Kurt Roeckx wrote:
> > On Wed, Dec 11, 2013 at 10:26:32PM +0100, Christoph Biedl wrote:
> > > Package: ntpdate
> > > Version: 1:4.2.6.p5+dfsg-2
> > > Severity: normal
> > > Tags: patch
> > > 
> > > Dear Maintainer,
> > > 
> > > the code in /etc/network/if-up.d/ntpdate tries to prevent parallel
> > > excution of ntpdate-debian by perusing the lockfile-progs package. If
> > > this is not installed - and it seldom is here -,
> 
> With the switch to systemd by default, the problem appears at almost all
> boots, even with -u is not added to /etc/default/ntpdate.
> 
> > You know there is a:
> > Recommends: lockfile-progs
> 
> The problem now affects all users using systemd which is the default for
> Jessie. In that case a Recommends: is clearly not enough. I am therefore
> bumping the severity of this bug.
> 
> > I didn't know about flock(1), will look in to it.
> 
> I'll see if I can come with a patch.

Here is a possible patch. I set the timeout to 180 seconds, which is the
default value in lockfile-progs.


--- ntp-4.2.6.p5+dfsg/debian/ntpdate.if-up
+++ ntp-4.2.6.p5+dfsg/debian/ntpdate.if-up
@@ -33,17 +33,9 @@
 LOCKFILE=/var/lock/ntpdate
 
 # Avoid running more than one at a time
-if [ -x /usr/bin/lockfile-create ]; then
-	lockfile-create $LOCKFILE
-	lockfile-touch $LOCKFILE &
-	LOCKTOUCHPID="$!"
-fi
-
-/usr/sbin/ntpdate-debian -s $OPTS 2>/dev/null || :
-
-if [ -x /usr/bin/lockfile-create ] ; then
-	kill $LOCKTOUCHPID
-	lockfile-remove $LOCKFILE
-fi
+(
+	flock -w 180 -x 9 || exit 1
+	/usr/sbin/ntpdate-debian -s $OPTS 2>/dev/null || :
+) 9>$LOCKFILE
 
 ) &


-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
aurelien at aurel32.net                 http://www.aurel32.net